o expect the disk's start routine to return an int. If the
int is non-zero, we enqueue the request and try again
later.
o have a dk_start() routine which runs the request queue.
o have a dk_iodone() function which should be called by the
driver using the framwork from its iodone. dk_iodone will
retry the queue since presumably further progress may be
possible once a request is complete. It is required that
the underlying driver have the resources to keep at least
one transaction in flight at any time.
Modified cgd to:
o be able to keep one transaction in flight at any time
(almost) by keeping a buffer of size MAXPHYS in its softc
and use it.
We still need to make the cgd_cbufpool per device rather than global
and provide a low water mark for it.
Addresses PR: kern/24715
(at least according to the submitter.)
This is an incompatible change, and will break all existing cgd images
encrypted with blowfish. Users will need to dump their data before
booting a kernel with this change, and recreate cgd's and restore data
afterwards.
I believe this affects a very small number of users other than myself;
indeed after several alert mails in an attempt to find them, only 2
such users have come forward. They have both agreed the requirement
for backwards compatibility does not warrant the effort nor the mess
in the code. This code does exist, if it should later prove to be
needed, but will not be in the tree.
Further, by the nature of the issue, I have strong reasons to believe
that, even if they missed these mails, there would be few other users
of blowfish who update their systems with any regularity; any such
users would have tripped over the problem in the same way I did when
it was first found over a year ago.
The problem stems from two issues with the underlying blowfish
encryption routines used by cgd:
- they take key length arguments counted in bytes, rather than bits
like all the opther ciphers.
- they silently truncate any keys longer than an internal limit,
rather than returning an error (which would have exposed the
previous discrepancy immediately).
As a result, the kernel reads too much data as the key from cgdconfig,
and then truncates most of it. This can easily be demonstrated/tested.
Currently, Blowfish users will find that if they mis-enter the cgd
passphrase on the first attempt, when validation fails and cgdconfig
prompts for the passphrase again, the cgd will not correctly configure
even when given a correct passphrase.
VOP_STRATEGY(bp) is replaced by one of two new functions:
- VOP_STRATEGY(vp, bp) Call the strategy routine of vp for bp.
- DEV_STRATEGY(bp) Call the d_strategy routine of bp->b_dev for bp.
DEV_STRATEGY(bp) is used only for block-to-block device situations.
be inserted into ktrace records. The general change has been to replace
"struct proc *" with "struct lwp *" in various function prototypes, pass
the lwp through and use l_proc to get the process pointer when needed.
Bump the kernel rev up to 1.6V
- disk_unbusy() gets a new parameter to tell the IO direction.
- struct disk_sysctl gets 4 new members for read/write bytes/transfers.
when processing hw.diskstats, add the read&write bytes/transfers for
the old combined stats to attempt to keep backwards compatibility.
unfortunately, due to multiple bugs, this will cause new kernels and old
vmstat/iostat/systat programs to fail. however, the next time this is
change it will not fail again.
this is just the kernel portion.
